Since the two previous rotifer symposia in Lunz and Gent were highly successful, it was considered important to continue the tradition every third year. Thus a third rotifer symposium was held in Uppsala, Sweden, Aug. 30-Sept. 4, 1982. In the beginning of 1981 the first circular was mailed to the participants of the previous symposia, who in turn were requested to suggest names of other scientists to be invited. As a result many people expressed interest, about 70 of whom finally participated in the symposium (not including temporary visitors from nearby). The participants represented 22 countries, in Europe, North America, Asia and Australia. As with the earlier symposia, some subjects were selected in advance, mainly during discussions between Henri Dumont, Birger Pejler and Peter Starkweather when they met at the SIL congress in Kyoto 1980. Some broad topics such as 'Marine rotifers' were covered for the first time, while other topics were continuations, though more specialized, of previous themes. Thus it is interesting to follow, through the three symposium volumes, recent development within the areas of feeding, popUlation dynamics and ultrastructure. Each prospective participant (with the exception of the reviewers) was invited to present one short paper (alone or with collaborators), which resulted in more than 40 such contributions. Thus, the week's schedule became very crowded, unfortunately leaving no time for more comprehensive workshops etc. However, during the evenings general discussions were held on the topics presented during the day.

Inhalt

One: Taxonomy and Evolution.- 1. Rotifera or Rotatoria?.- 2. Parallelism in the evolution of rotifers.- 3. Rotifera from Western Australian wetlands with descriptions of two new species.- Two: Geographical Distribution.- 4. Biogeography of rotifers.- 5. The Indian species of the genus Brachionus (Eurotatoria: Monogononta: Brachionidae).- 6. Rotifer communities of billabongs in northern and south-east Australia.- 7. Rotifera from northeastern Quebec, Newfoundland and Labrador, Canada.- 8. Rotifers of the Antarctic and Subantarctic.- Three: Culturing and Related Methods.- 9. Environmental factors affecting hatching of rotifer (Brachionus plicatilis) resting eggs.- 10. Continuous culture of the rotifer Brachionus plicatilis fed recycled algal diets.- 11. Production of the rotifer Brachionus plicatilis for aquaculture in Kuwait.- 12. Cryopreservation of monogonont rotifers.- Four: Structure.- 13. Behavior and ultrastructure of sensory organs in rotifers.- 14. Some historical specimens of rotifers examined by scanning electron microscopy.- Five: Biochemistry and Aging.- 15. A re-examination of the Lansing Effect.- 16. Aging in Brachionus plicatilis: The evolution of swimming as a function of age at two different calcium concentrations.- 17. Macromolecular synthesis during embryogenesis of Habrotrocha rosa Donner I. Replication of DNA.- 18. Cholinergic neurotransmission in rotifers.- Six: Ecology: Laboratory And Field Studies.- 19. Rotifer nutrition using supplemented monoxenic cultures.- 20. Control of sexuality in Asplanchna brightwelli: threshold levels of dietary tocopherol and modification of tocopherol response by exogenous and endogenous factors.- 21. Life histories of some species of Rotifera Bdelloidea.- 22. The significance of mating processes for the genetics and for the formation of resting eggs in monogonont rotifers.- 23. Phototaxis in monochromatic light and microspectrophotometry of the cerebral eye of the rotifer Brachionus Calyciflorus.- 24. An experimental system for the automatic tracking and analysis of rotifer swimming behaviour.- 25. Sensory receptors involved in the feeding behaviour of the rotifer Asplanchna brightwelli.- 26. Resting eggs in rotifers.- 27. On temperature acclimation in an experimental population of Brachionus calyciflorus.- 28. The Rotatoria-Monogononta of the River Drava in Slovenia, Yugoslavia.- 29. Ammonia nitrogen and inorganic phosphorus excretion by the planktonic rotifers.- 30. Comparative studies on the relationship between temperature and duration of embryonic development of rotifers.- 31. Composition, dynamics and production of Rotatoria in the plankton of some lakes of the Danube Delta.- 32. Vertical distribution and rotifer concentrations in the chemocline of meromictic lakes.- 33. Changes in the relative abundance of Polyarthra vulgaris and P. dolichoptera, following the elimination of fish.- 34. Seasonal abundance of psammon rotifers.- 35. Biometric analysis of Brachionus plicatilis ecotypes from Spanish lagoons.- 36. Comparative analysis of plankton rotifer biomass in large Estonian lakes.- 37. Morphological variation of Keratella cochlearis (Gosse) in Lake Biwa, Japan.- 38. Notes on the rotifers of coal mine water in Eastern Poland.- 39. Rotifer occurrence in relation to water temperature in Loch Leven, Scotland.- 40. Substrate selection and larval settlement by Cupelopagis vorax.- 41. Changes in growth and size of Keratella Cochlearis (Gosse) in relation to some environmental factors in cultures.- 42. Production of planktonic Rotatoria in Ormajärvi, an eutrophicated lake in southern Finland.- 43. Annual dynamics and production of rotifers in an eutrophication gradient in the Baltic Sea.- 44. Occurrene of Rotifera in the field under natural and intentionally-changed conditions.- 45. Abundance, dynamics and succession of planktonic rotifers in Lake Biel, Switzerland.- 46. Community structure of planktonic rotifers in a mesotropic lake.- 47. Rotifers as indicators of lake types in Estonia.- 48. Interactions between Asplanchna and Keratella cochlearis in the Plußsee.- 49. Empty loricas and the dynamics of Kellicottia longispina in a subalpine, oligotrophic lake.- 50. Utilization of cyanobacteria by Brachionus calyciflorus: Anabaena flos-aquae (NRC-44-1) as a sole or complementary food source.- 51. Clearance rates of sessile rotifers: In situ determinations.- 52. Invertebrate predation of planktonic rotifers.